The problems with such torrent search engines are:
So far I have not received such letters as I'm the owner of a public searx instance. It would be nice (for some restrictive countries) to have a way to fully exclude torrent search engines allowing such content being tracked there. So every admin (and end-user can see it in settings page) can decide it independently from searx' decision.
So it has pros and cons to have such engines in. E.g. you might better want to have torrent trackers in that track only OSS/FLOSS to spread the good word about trorrents.
We already have loads of search engines like that in the code base for a long time: TBP, torrentz2, 1337x, kickass, nyaa, seedpeer.
I don't think another one will make the difference and you are free to disable the engines that you don't want on your own public instance.
Moreover Searx is a still a niche project and the law enforcement target popular websites not a small website used by only 200 visitors by day.
If it helps, we should document the xpath engine and add some code snippets (examples) to that docs.
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We already have loads of search engines like that in the code base for a long time: TBP, torrentz2, 1337x, kickass, nyaa, seedpeer.
I don't think another one will make the difference and you are free to disable the engines that you don't want on your own public instance.
Moreover Searx is a still a niche project and the law enforcement target popular websites not a small website used by only 200 visitors by day.